Hi there- hope you have a wonderful time on your trip. I had actually not planned on doing many booked excursions but once I got on the cruise I realized they were the most practical way of getting around,that we would see more that way and not have the worry of getting back to the ship. I didn't end up feeling they were too expensive either. If you don't book excursions you might spend alot of time making your own arrangements. However, Santorini and Mykonos are two places you really can do on your own. They are both small and we walked and rode the local buses for the wee journeys we needed to take. I would do it the same way again. It was no problem in those two places. Write again if you have any more questions. It does help to talk to others who have been there. I had a friend who had worked for a cruise line and she gave me lots of good tips before I left. bon Voyage. Kim